When higher-viscosity liquids such as polyurethane or silicone raw materials are used to produce gaskets or the like, the pre-treatment of said viscous materials is of great importance for the quality of the product produced thereafter. The raw materials used are often one or two components of a multi-component system, which are thoroughly mixed in a mixer and then chemically react with each other to produce a gas, usually carbon dioxide, and then, after being ejected from the mixer and applied to a substrate, they foam. This enables the production of Formed in Place-Foamed Gaskets, “FiPFG”.
In particular when using silicone materials to produce said foamed gaskets or coverings, the air content of the relatively highly-viscous starting material is of particular importance in obtaining good foam quality. The materials used, in particular silicone materials, must preferably be loaded with a precisely controlled amount of air before being processed further, e.g. being mixed with a second component in a mixer, in other words, with air dissolved in the liquid under increased liquid pressure, which forms nuclei for the gas bubbles produced in the subsequent chemical reaction, to which the gas produced in the chemical reaction can attach and thus form a foam of particularly high quality.